LIGHT READING INLAND POWER AND LIGHT inlandpower.com
SEPTEMBER 2018
Anatomy of a Power Pole? You likely don’t pay much attention to the utility poles found throughout Inland Power’s service area, but we do and these structures are the backbone of our electric distribution network. Your cooperative has 5,241 miles of overhead power lines (and 1,956 of underground) strung across 101,897 wooden poles throughout our service area comprising 13 counties. Not all poles have all equipment pictured on them as they vary according to
What’s on an Electric Power location and the servicePole? they provide. This is an illustration of basic equipment found on a typical distribution pole and can vary by location.
Insulators prevent energized wires from coming in contact with each other or the utility pole.
A crossarm holds the wires up on the pole and away from other wires or pole. Lightning arrestors protect the pole and equipment from lightning strikes.
Transformers convert higher voltage electricity carried by primary wires and lowers the voltage for use by customers. A ground wire runs the entire length of the pole. It directs any stray voltage on the pole safely into the earth.
Primary wires are on top of the pole and usually carry 7,200 volts of electricity from a substation.
Cutouts act like a fuse and open when there is a problem with the line or a section of it. The neutral wire is below the transformer and balances out the amount of electricity or load on the system.
The secondary wire carries the lower voltage electricity to the home after it passes through the transformer.
Telephone and cable wires are typically the lowest wires.
Guy wires help stabilize utility poles.
Providing Power to Our Valued Members How it all works. Inland’s BPA/ Avista transmission lines operate at anywhere from 115,000 to 500,000 volts and attach to large insulators on tall wooden or most typically, metal structures. Electrical energy from the transmission lines are then converted to a distribution voltage of 7,200 volts at a substation. At the substation, the energy is then separated into multiple circuits, often called A, B, or C phase for distribution to your home. At 7,200 volts, the voltage is still too high for your home, so distribution transformers, as seen to the left, step down the voltage again to the level required for your home; 120 or 240 volts. The 7,200 volt lines are called primary lines and the 120/240 volt lines are called secondary lines. The secondary line, usually an insulated black wire, is then connected to your home’s meter box, which provides the means for tracking energy use and electrifying your home.
Providing safe, reliable electricity to you is our specialty!